p-Toluenesulfonamides

Ts-NR_2, , Tosylamides

T. W. Green, P. G. M. Wuts,
Protective Groups in Organic Synthesis,
Wiley-Interscience, New York, 1999, 604-607, 744-747.

Stability

H2O:	pH < 1, 100°C	pH = 1, RT	pH = 4, RT	pH = 9, RT	pH = 12, RT	pH > 12, 100°C
Bases:	LDA	NEt3, Py	t-BuOK	Others:	DCC	SOCl2
Nucleophiles:	RLi	RMgX	RCuLi	Enolates	NH3, RNH2	NaOCH3
Electrophiles:	RCOCl	RCHO	CH3I	Others:	:CCl2	Bu3SnH
Reduction:	H2 / Ni	H2 / Rh	Zn / HCl	Na / NH3	LiAlH4	NaBH4
Oxidation:	KMnO4	OsO4	CrO3 / Py	RCOOOH	I2, Br2, Cl2	MnO2 / CH2Cl2

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Protection

A facile and efficient indium-catalyzed sulfonylation of amines allows the synthesis of a wide range of sulfonamides in excellent yields. The method showed a generality for substrates including less nucleophilic and sterically hindered anilines, and it is also applicable for preparing sulfonic esters from sulfonyl chlorides and alcohols.
J. Yan, J. Li, D. Cheng, Synlett, 2007, 2442-2444.

An easy and handy synthesis of sulfonamides directly from sulfonic acids or its sodium salts is performed under microwave irradiation, has shown a good functional group tolerance, and is high yielding.
L. De Luca, G. Giacomelli, J. Org. Chem., 2008, 73, 3967-3969.

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Deprotection

The reaction of different protected alcohols, amines and amides with lithium and a catalytic amount of naphthalene in THF at low temperature leads to their deprotection under very mild reaction conditions, the process being in many cases chemoselective.
E. Alonso, D. J. Ramón, M. Yus, Tetrahedron, 1997, 53, 14355-14368.

E. Alonso, D. J. Ramón, M. Yus, Tetrahedron, 1997, 53, 14355-14368.

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Conversion of Tos-protected Amines to other functional groups

A mild deprotection for notoriously difficult to unmask primary N-(p-toluenesulfonyl) amides occurs at low temperature by initial activation of the nitrogen with a trifluoroacetyl group, followed by reductive cleavage of the p-toluenesulfonyl group with samarium diiodide.
Z. Moussa, D. Romo, Synlett, 2006, 3294-3298.